Gains were strong for minority students: African-American students saw a 6.9 percent increase in graduation rates from 2006 to 2020, and Hispanic students had a 10.4 percent increase.

In the Davis Guggenheim documentary “Waiting for Superman,” Americans learned about “dropout factories,” high schools where fewer than half of all students graduated on time. Bob Balfanz, a Johns Hopkins University professor, coined that term — and in the report out Monday, he found that the number of “dropout factories” has declined. In 2011, according to the report, there were 583 fewer such schools than there were in 2002. “The schools have gotten better, and some have closed,” Balfanz said.

In 2002, 46 percent of black students and 39 percent of Hispanics attended a high school where most students failed to graduate. By 2011, that fell to 25 percent for backs and 17 percent for Hispanics.

Besides causing an outcry among parents and teachers, this approach hasn’t always yielded all positive benefits, as we’ve written about previously. (For an in-depth look at the arduous process of closing a school, I recommend the GothamSchools series that has followed the effort to shut down Columbus High School in the Bronx along with two others.)

The city also created “alternate pathways for at-risk students so they could catch up on missed credits or return to school after dropping out.”

While black, Hispanic and Native American students made the greatest gains, only 40 percent graduated on time in 2008, notes Education Week.

The report recommended a number of strategies:

These include targeting schools with high dropout rates and the lower grades that feed into them; providing more-rigorous course requirements along with more flexible class schedules for students; and developing early-warning systems to identify students in earlier grades at risk of dropping out, among other strategies.

To qualify for federal education grants, states and districts must track students from eighth grade through graduation, starting in 2010-11, and start showing improvement in 2011-12. Requiring a consistent reporting method will stop districts from inflating graduation rates, says Joanna Fox of Johns Hopkins.

Some cities are persuading more students to stay in school, according to the America’s Promise Alliance survey on dropouts. On average, only half of students in big cities graduate. However, Philadelphia, Tucson and Kansas City boosted their graduation rates by 20 percentage points or more over a decade; 10 more cities saw double-digit improvements.

. . . long waiting lists for adult education and GED — General Education Development — classes, spiking enrollments at community colleges and, perhaps, a surge in returns by high-school dropouts and a decline in those who leave in the first place, may all point to a renewed focus on education, experts say.

For every 1 percentage point rise in the unemployment rate, the dropout rate falls by 5 percent, one study found.